Problem with my .257 Weatherby brass

Hello all, this is my first post. I hope I'm not making it incorrectly. Anyways, I'm having problems seating my bullets in my .257. I'm trying to load both 110gr accubonds and 115gr TSX's. My brass is factory and they were loaded with 120gr Partitions. Does the crimp from the partitions affect the size of the fired brass? With my other brass I can drop a bullet in it until I size it, not the Weatherby. I figured after I resized it the problem would go away, nope... I ran a caliper over all of my bullets and they are .257, my factory loads are .257, and my fired brass is .253 inside dia., and .283 outside dia.. When I try seating a bullet it crushes my brass. What am I doing wrong? Thanks, Josh.

Thanks for replying. After sitting here for a couple of hours thinking about it, I went back at it. What happened was I made a pretty good rookie mistake. I was upset with my powder dispenser. It was giving me powder loads all over the place. It took me 2 hrs to get powder for six shells... Anyways in the mean time I adjusted my seater without the shell holder... I should have just quit until I got refocused. Thanks for time and sorry for bothering everyone, Josh.